The present invention relates to a projectile arrangement including a subcaliber projectile body and a segmented discardable propelling cage sabot. More particularly, the present invention relates to a projectile arrangement including a subcaliber projectile body, a segmented, discardable propelling cage sabot which at least partially surrounds the projectile body and a common form locking zone formed in this enclosed region for transmitting acceleration forces from the propelling cage sabot to the projectile body with the form locking zone being composed, at least in part, of corresponding thread grooves or annular grooves structurally worked into the exterior surface of the projectile body and into the interior surface of the propelling cage sabot or the propelling cage sabot segments.
A projectile arrangement of the above type is disclosed, for example, in German Patent No. 2,234,219 corresponding to U.S. Pat. No. 4,671,181. The armor piercing projectile disclosed there has a breakage susceptible core of tungsten carbide which is encased by a ductile steel jacket. The conventional threaded grooves for a form locking connection with the sabot are here cut into the outer surface of the steel jacket or casing of the projectile body so as to reduce the susceptibility to breakage of the brittle heavy metal core and prevent breaking of the core during penetration of armored targets, particularly those composed of multiple armor plates. Particularly in such armors composed of several substances, the different characteristics of the material of the individual armor layers, e.g. alternating layers of armor steel, plastic and ceramic material, generate strong transverse forces on the slender penetrator rod leading to premature breakage and failure of the penetrator.
This prior art projectile, due to its breakage susceptibility reducing steel casing configuration, is excellently suited for use against armored targets, but its drawback is the reduction of kinetic energy due to a reduction in the average density of the projectile body as a result of the "lightweight" contribution of the steel casing. Moreover, the manufacture of this prior art projectile body is rather complicated and expensive.
Customarily, form locking zones are composed of thread grooves and not of individual annular grooves. The reason for this is that it is much easier from a manufacturing point of view to use available tools (thread cutters) for cutting a thread into the central inner bore of the propelling cage, which, for example, has a diameter of only 42 mm (equal to the diameter of the projectile body) than to cut equidistant annular grooves into the inner bore with a rotary cutter that has to be newly placed for each annular groove.
A subcaliber penetrator made of a tungsten alloy and equipped with a segmented propelling cage is shown, for example, at page 474 of the periodical "Internationale Wehrrevue" (International Weapons Review) Vol. 5/1988. This penetrator has a form locking zone which is composed of cut-in thread grooves and extends over almost the entire length of the projectile. If the projectile is employed against multi-armor plate targets, the generated transverse forces may lead to premature breakage and loss of performance of the penetrator, with the sharp notches in the bottom of the thread acting, so to speak, as predetermined break locations.